sábado, 4 de fevereiro de 2012

This
false-color view of Toro Crater on Mars was captured on Dec. 1, 2011,
by the High Resolution Imaging Science Experiment on NASA's Mars
Reconnaissance Orbiter, and released on Wednesday. The different colors
reflect different mineral composition on the Martian surface.

By Alan Boyle

There's
not much red in this picture of the Red Planet, produced by the
high-resolution camera aboard NASA's Mars Reconnaissance Orbiter. Browns
and blues and greens and yellows and violets ... but red? Not so much.
There's a method in this colorful madness: The riot of color tells
scientists that, mineralogically speaking, this is a wildly diverse
region of Mars.
The orbiter took this picture of Toro Crater in
Mars' northern hemisphere back on Dec. 1, and the processed version was
released just this week. The University of Arizona's Alfred McEwen,
principal investigator for the High Resolution Imaging Science
Experiment or HiRISE, says the different colors point to different kinds
of minerals that may have been altered through the action of liquid
water and heat on ancient Mars.

advertisement

HiRISE's views in different wavelengths can be tweaked to tell
geologists things about surface composition that you might not notice in
a "true color" photograph.
"In general, the blue and green colors
indicate unaltered minerals like pyroxene and olivine, whereas the
warmer colors indicate alteration into clays and other minerals," McEwen writes in his image advisory. "The linear north-south trending features are windblown dunes that are much younger than the bedrock."
Such hydrothermal alteration could get a closer examination elsewhere on Mars when NASA's Curiosity rover touches down in Gale Crater this August.
For more of this crazy imagery, check out this longer, higher-resolution view of the Toro Crater scene. If you've got red-blue glasses, you'll get a kick out of this 3-D version. The HiRISE home page
will point you to thousands of pictures from Mars — some in true color,
some in false color, some in black and white, and some in 3-D red and
blue. Feel free to go crazy.

S. Robbins / Moon Mappers / CosmoQuest / NASA

This
image of the moon shows craters that have been identified by citizen
scientists as part of the Moon Mappers project. The blue circles
indicate raw IDs by individual users, while the red circles indicate
craters identified by a computer program that groups together individual
markings.

Scientists have long studied craters on the moon to trace the
evolution of the solar system. The distribution and estimated ages of
lunar craters have led astronomers to conclude, for example, that the
inner solar system weathered a hailstorm of impacts known as the "Late Heavy Bombardment" about 4 billion years ago.
Crater counting is a valuable exercise, but it's hard to automate. Moon Mappers, a project presented by the CosmoQuest website, is
calling upon the wisdom of crowds to help scientists make sense out of
the imagery being sent back to Earth by NASA's Lunar Reconnaissance
Orbiter. Similar citizen-science projects, organized by Zooniverse,
have yielded published research — and Moon Mappers is likely to be
similarly productive. So if you want to take part in some real science,
consider joining the Moon Mappers team.
The moon picture was doubly apt, because of the Moon Mappers angle as well as the past week's political debates over future moon missions. For the latest word in that debate, check out this commentary by NBC News' longtime Cape Canaveral correspondent, Jay Barbree.
I posted this week's "Where in the Cosmos" picture puzzle
earlier today, and within an hour several Cosmic Log Facebookers
figured out that it was a 3-D view of the Snowman crater chain on the
asteroid Vesta, as seen by NASA's Dawn probe. This means that Jarin
Udom, Joan Tweedell and Ryan Anthony Sebastian Carroll join Robert
Dryden in the winner's circle. They're all eligible to receive 3-D
glasses once I get their mailing addresses.

To get in on the next "Where in the Cosmos" puzzle, be sure to hit the "Like" button on the Cosmic Log Facebook page ... and if you're already a fan, thanks for being part of the community!More fun with space pictures: